In 1988, the World Health Assembly resolved to eradicate poliomyelitis globally by 2000. Substantial progress has been achieved toward this goal, and with the circulation of wild poliovirus eliminated in most of the world, attention has focused on examining the potential for vaccine-derived poliovirus to circulate where wild poliovirus has disappeared. During 1999, sequences of historic poliovirus isolates were examined. This report summaries the results of that study, which indicate that oral poliovirus vaccine (OPV)-derived poliovirus type 2 circulated in Egypt during the 1980s and early 1990s and caused widespread infection and paralytic disease. The findings underscore the need for countries using OPV to target communities with low vaccine coverage for intense vaccination activities to prevent circulation of both wild and vaccine-derived polioviruses.